/* reading, checking and/or writing header and node information
*/
void
markfromheader (FileOffset *buf)
{
fseek(f,8L,SEEK_SET);
fread(buf,sizeof(FileOffset),2,f);
markfrom(getpointer(buf+1),buf+1);
markfrom(getpointer(buf), buf);
}
/* reading, checking and/or writing header and node information
*/
void
markfromheader (uint32_t *buf)
{
fseek(f,8L,SEEK_SET);
fread(buf,sizeof(uint32_t),2,f);
markfrom(getpointer(buf+1),buf+1);
markfrom(getpointer(buf), buf);
}
void
markfromoutput (char *bridgefile, FileOffset *buf)
{
FILE* bridge = fopen(bridgefile, "rb");
if (bridge==(FILE*)0) return;
for (;;) {
int n = fread(buf,sizeof(FileOffset),1,bridge);
if (n<1) return;
markfrom(getpointer(buf),buf);
}
fclose(bridge);
}
/* mark all the nodes in the hat file that are reachable
* from the given root -- setting the highest bit in the
* tag byte
*/
void
markfrom (FileOffset root, FileOffset *buf)
{
char tag;
if (root > 8 && root < filesize) {
/* First read the tag byte. If it is marked, return.
* If it is not marked, then mark it now.
*/
fseek(f,(long int)root,SEEK_SET);
fread(&tag,sizeof(char),1,f);
if (ismarked(tag)) return;
marktag(&tag);
fseek(f,(long int)root,SEEK_SET);
fwrite(&tag,sizeof(char),1,f);
cleartag(&tag);
/* Examine the tag to determine the kind of node.
* Read pointers from the node into buf, then
* markfrom() these pointers recursively. The buffer is
* overwritten where possible to minimise the risk of overflow:
* for this reason, pointers are recursively traced in
* reverse order.
*/
{
int k = lo5(tag);
if ((ExpDoStmt < k && k < AtomVariable) || k > ListCons) {
fprintf(stderr, "strange tag %d at 0x%x\n",
k, root);
exit(1);
}
switch (k) {
case ListCons:
fread(buf,sizeof(FileOffset),2,f); /* two pointers */
markfrom(getpointer(buf+1),buf+1);
markfrom(getpointer(buf),buf);
break;
case Module: break;
case AtomAbstract: break;
case SrcPos:
case AtomVariable:
case AtomConstructor: /* ignore fieldnames for now */
fread(buf,sizeof(FileOffset),1,f); /* points to module mode */
markfrom(getpointer(buf),buf);
break;
default: {
int pos = 0;
if (hasSrcPos(tag)) {
fread(buf+pos,sizeof(FileOffset),1,f);
pos++;
}
fread(buf+pos,sizeof(FileOffset),1,f); /* parent pointer */
pos++;
switch (k) {
case ExpApp:
fread(buf+pos,sizeof(FileOffset),2,f); /* result+fun */
pos += 2;
{ unsigned char arity;
fread(&arity,sizeof(unsigned char),1,f);
fread(buf+pos,sizeof(FileOffset),(unsigned int)arity,f);
pos += (int)arity;
}
break;
case ExpValueApp:
fread(buf+pos,sizeof(FileOffset),1,f); /* fun */
pos += 1;
{ unsigned char arity;
fread(&arity,sizeof(unsigned char),1,f);
fread(buf+pos,sizeof(FileOffset),(unsigned int)arity,f);
pos += (int)arity;
}
break;
case ExpValueUse:
case ExpConstUse:
case ExpProjection:
fread(buf+pos,sizeof(FileOffset),1,f); /* one extra pointer */
pos++;
break;
case ExpHidden:
case ExpConstDef:
case ExpFieldUpdate: /* ignore fieldnames for now */
case ExpGuard:
case ExpCase:
case ExpIf:
fread(buf+pos,sizeof(FileOffset),2,f); /* two pointers */
pos+=2;
break;
default: break; /* no pointers */
}
for (;pos-->0;) markfrom(getpointer(buf+pos), buf+pos);
} break;
}
}
}
}
